Need more info, What are you intentions with the car? How much compression? What kind of gears? What trans? What kind of RPM do you wish to operate? Where do you want to make power?
My advice call Competition Cams tell them what you have and they will be able to tell you what cam you should run with your specific set up. Then you wont be quessing
Why convert the transmission, that FMX will easily handle a 347. Unless you just want a manual transmission. But then the FMX was offered at one time with a manual shift mode.